const formatTime = date => {
  const year = date.getFullYear()
  const month = date.getMonth() + 1
  const day = date.getDate()
  const hour = date.getHours()
  const minute = date.getMinutes()
  const second = date.getSeconds()

  return [year, month, day].map(formatNumber).join('/') + ' ' + [hour, minute, second].map(formatNumber).join(':')
}

const formatNumber = n => {
  n = n.toString()
  return n[1] ? n : '0' + n
}


function formatDate(v, format) {
  var formateArr = ['Y', 'M', 'D', 'h', 'm', 's'];
  var returnArr = [];
  var date = new Date(v);
  returnArr.push(date.getFullYear());
  returnArr.push(formatNumber(date.getMonth() + 1));
  returnArr.push(formatNumber(date.getDate()));
  returnArr.push(formatNumber(date.getHours()));
  returnArr.push(formatNumber(date.getMinutes()));
  returnArr.push(formatNumber(date.getSeconds()));
  for (var i in returnArr) {
    format = format.replace(formateArr[i], returnArr[i]);
  }
  return format;
}
var Base64 = {
  // 转码表  
  table: [
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
    'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
    'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
    'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
    'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
    'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
    'w', 'x', 'y', 'z', '0', '1', '2', '3',
    '4', '5', '6', '7', '8', '9', '+', '/'
  ],
  UTF16ToUTF8: function (str) {
    var res = [], len = str.length;
    for (var i = 0; i < len; i++) {
      var code = str.charCodeAt(i);
      if (code > 0x0000 && code <= 0x007F) {
        // 单字节，这里并不考虑0x0000，因为它是空字节  
        // U+00000000 – U+0000007F  0xxxxxxx  
        res.push(str.charAt(i));
      } else if (code >= 0x0080 && code <= 0x07FF) {
        // 双字节  
        // U+00000080 – U+000007FF  110xxxxx 10xxxxxx  
        // 110xxxxx  
        var byte1 = 0xC0 | ((code >> 6) & 0x1F);
        // 10xxxxxx  
        var byte2 = 0x80 | (code & 0x3F);
        res.push(
          String.fromCharCode(byte1),
          String.fromCharCode(byte2)
        );
      } else if (code >= 0x0800 && code <= 0xFFFF) {
        // 三字节  
        // U+00000800 – U+0000FFFF  1110xxxx 10xxxxxx 10xxxxxx  
        // 1110xxxx  
        var byte1 = 0xE0 | ((code >> 12) & 0x0F);
        // 10xxxxxx  
        var byte2 = 0x80 | ((code >> 6) & 0x3F);
        // 10xxxxxx  
        var byte3 = 0x80 | (code & 0x3F);
        res.push(
          String.fromCharCode(byte1),
          String.fromCharCode(byte2),
          String.fromCharCode(byte3)
        );
      } else if (code >= 0x00010000 && code <= 0x001FFFFF) {
        // 四字节  
        // U+00010000 – U+001FFFFF  11110xxx 10xxxxxx 10xxxxxx 10xxxxxx  
      } else if (code >= 0x00200000 && code <= 0x03FFFFFF) {
        // 五字节  
        // U+00200000 – U+03FFFFFF  111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx  
      } else /** if (code >= 0x04000000 && code <= 0x7FFFFFFF)*/ {
        // 六字节  
        // U+04000000 – U+7FFFFFFF  1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx  
      }
    }

    return res.join('');
  },
  UTF8ToUTF16: function (str) {
    var res = [], len = str.length;
    var i = 0;
    for (var i = 0; i < len; i++) {
      var code = str.charCodeAt(i);
      // 对第一个字节进行判断  
      if (((code >> 7) & 0xFF) == 0x0) {
        // 单字节  
        // 0xxxxxxx  
        res.push(str.charAt(i));
      } else if (((code >> 5) & 0xFF) == 0x6) {
        // 双字节  
        // 110xxxxx 10xxxxxx  
        var code2 = str.charCodeAt(++i);
        var byte1 = (code & 0x1F) << 6;
        var byte2 = code2 & 0x3F;
        var utf16 = byte1 | byte2;
        res.push(String.fromCharCode(utf16));
      } else if (((code >> 4) & 0xFF) == 0xE) {
        // 三字节  
        // 1110xxxx 10xxxxxx 10xxxxxx  
        var code2 = str.charCodeAt(++i);
        var code3 = str.charCodeAt(++i);
        var byte1 = (code << 4) | ((code2 >> 2) & 0x0F);
        var byte2 = ((code2 & 0x03) << 6) | (code3 & 0x3F);
        var utf16 = ((byte1 & 0x00FF) << 8) | byte2
        res.push(String.fromCharCode(utf16));
      } else if (((code >> 3) & 0xFF) == 0x1E) {
        // 四字节  
        // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx  
      } else if (((code >> 2) & 0xFF) == 0x3E) {
        // 五字节  
        // 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx  
      } else /** if (((code >> 1) & 0xFF) == 0x7E)*/ {
        // 六字节  
        // 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx  
      }
    }

    return res.join('');
  },
  encode: function (str) {
    if (!str) {
      return '';
    }
    var utf8 = this.UTF16ToUTF8(str); // 转成UTF8  
    var i = 0; // 遍历索引  
    var len = utf8.length;
    var res = [];
    while (i < len) {
      var c1 = utf8.charCodeAt(i++) & 0xFF;
      res.push(this.table[c1 >> 2]);
      // 需要补2个=  
      if (i == len) {
        res.push(this.table[(c1 & 0x3) << 4]);
        res.push('==');
        break;
      }
      var c2 = utf8.charCodeAt(i++);
      // 需要补1个=  
      if (i == len) {
        res.push(this.table[((c1 & 0x3) << 4) | ((c2 >> 4) & 0x0F)]);
        res.push(this.table[(c2 & 0x0F) << 2]);
        res.push('=');
        break;
      }
      var c3 = utf8.charCodeAt(i++);
      res.push(this.table[((c1 & 0x3) << 4) | ((c2 >> 4) & 0x0F)]);
      res.push(this.table[((c2 & 0x0F) << 2) | ((c3 & 0xC0) >> 6)]);
      res.push(this.table[c3 & 0x3F]);
    }

    return res.join('');
  },
  decode: function (str) {
    if (!str) {
      return '';
    }

    var len = str.length;
    var i = 0;
    var res = [];

    while (i < len) {
      var code1 = this.table.indexOf(str.charAt(i++));
      var code2 = this.table.indexOf(str.charAt(i++));
      var code3 = this.table.indexOf(str.charAt(i++));
      var code4 = this.table.indexOf(str.charAt(i++));

      var c1 = (code1 << 2) | (code2 >> 4);
      var c2 = ((code2 & 0xF) << 4) | (code3 >> 2);
      var c3 = ((code3 & 0x3) << 6) | code4;

      res.push(String.fromCharCode(c1));

      if (code3 != 64) {
        res.push(String.fromCharCode(c2));
      }
      if (code4 != 64) {
        res.push(String.fromCharCode(c3));
      }

    }

    return this.UTF8ToUTF16(res.join(''));
  }
};
module.exports = {
  formatDate: formatDate,
  formatTime: formatTime,
  base64: Base64
}

